1,720,989 research outputs found
Prevalence and Characterization of Staphylococcus Species, Including MRSA, in the Home Environment
No full textThe purpose of this study is to assess the prevalence of Staphylococcus, including Methicillin-Resistant Staphylococcus aureus (MRSA), in a home environment. Staphylococcal species are among the most common bacteria causing joint infections, and emerging methicillin-resistant Staphylococcus aureus strains continue to remain a global problem. Staphylococci organisms commonly colonize the skin and nasal nares of healthy individuals, as well as livestock and other animals. There is a growing body of evidence that the environment (surfaces) plays an important role in the transmission of pathogens in the community.
MRSA can be spread from contaminated inanimate objects known as fomites. Many hard surfaces serve as good reservoirs for MRSA, including door knobs and hand rails. In this study, we assessed the prevalence of MRSA and other staphylococcal species in 76 homes across the central Texas area. This study will evaluate various Staphylococcus species found on four different areas of a home using a point prevalence design to detect the prevalence of MRSA.
A total of 304 swab samples from 76 different households were collected. Sources of collection included the inside front door handle, kitchen sink handle, most used remote control, and the refrigerator handle. One hundred and eighteen samples showed microbial growth (118/304, 38.8%), and 92 samples tested positive presumptively for S. aureus (92/304, 30.3%). Of those 92, four demonstrated oxacillin resistance and three were identified as MRSA (3/92, 3.4%) by displaying mauve colonies on CHROMagar. The findings of this study indicate potential exposure risks from Staphylococcus in everyday home environments, especially immunocompromised individuals.Clinical Laboratory Scienc
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Optimization of Molecular Buoys in the Isolation and Amplification of SARS-CoV-2 RNA in Wastewater
No full textWastewater based epidemiology (WBE) is an emerging tool used in the surveillance of viruses and viral diseases, such as SARS-CoV-2 and COVID-19. WBE comprises wastewater sampling and processing, isolation of target viruses and purification of target viral nucleic acids, and quantification through molecular means such as RT-qPCR. Isolation and purification is a crucial step in estimating viral loads and positivity rates in a given watershed. Current CDC-recommended methods in viral isolation can be costly, time consuming, or are otherwise inaccessible for widespread use. Our aim is to develop a rapid and accessible bio-separation method using inexpensive materials. In the present work, hollow silica microspheres, or “molecular buoys”, were functionalized with chitosan, a cationic polysaccharide, to capture nucleic acids in diluted stool. Scanning electron microscopy (SEM) was used to examine chitosan surface loading and fluorescently-tagged DNA aptamer (a surrogate oligonucleotide) diluted in stool was used to examine nucleic acid binding capacity. In addition, optimization of nucleic acid capture, reduction of assay time, and limit of detection (LOD) were explored. Under SEM, we observed a shell formation on the surface of chitosan-functionalized microspheres that was absent in non-functionalized microspheres. In addition, assay time was reduced by at least 15 - 20 minutes, bringing total assay time to around 35 - 40 minutes. Finally, the preliminary LOD was found to be 40 copies/uL in diluted stool. These findings suggest that functionalized hollow silica microspheres may be an effective, low-cost, and rapid method in the isolation of viral nucleic acids for use in WBE.Biolog
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Development of 2-D and 3-D Paper-based Microfluidic devices for the detection of Cryptosporidium and Giardia
No full textIn developing countries, morbidity due to infectious diseases such as diarrheal illness can cause major deterioration of physical and cognitive impairment in young children under the age of five and individuals with poor immune system. In such regions, proper diagnosis and treatment can help in changing the mortality and morbidity rates. Current tests used to detect diarrhea-causing pathogens are often expensive, time consuming, require a well-maintained centralized laboratory with continuous power supply, highly skilled laboratory personnel and good bio-safety practices, which are often limited in resource poor settings in both developed and developing countries. Real-time PCR, immunoassays (ELISA, or EIAs, lateral-flow test strips), microscopy, and flow cytometry are few examples of traditional tests available. The goal of this project was to develop a paper-based microfluidic device for detection of Cryptosporidium and Giardia, two protozoan pathogens that cause persistent to chronic diarrhea worldwide that is inexpensive and easy to use. Toward this goal, we designed and optimized a wax-printing technique to create microfluidic channels in paper that direct fluid flow via capillary action in defined patterns for colorimetric immunoassay detection of individual and multi-plexed pathogens. Initial results suggest that a minimum printed width of 300 µm was necessary to form an impermeable barrier in chromatography paper when heated at 95°C for 10 min, while a minimum channel width of 1500 µm was necessary to wick fluids through the microfluidic channels. Next, we performed a concentration series of immunolabeled Cryptosporidium oocysts and Giardia cysts to determine the lowest detectable number of oocysts in an enzyme-based colorimetric assay. Our results indicate that as few as 250 oocysts were visibly detectable for Cryptosporidium and 5000 cysts for Giardia. We further fabricated 3- dimensional (3-D) paper-based devices with a size- selective filter that excluded the use of cumbersome pre-labeling protocol to remove unbound-free antibodies by retaining enzyme-bound pathogens and measuring the amount of enzyme that reaches the bottom layer. Tests for size-selective membrane and 3-D retention assay using in-line filter holder showed that cellulose acetate membrane with 1.2 µm pore size was able to retain Cryptosporidium oocysts of size 4-6 µm. Follow-up assays for detection of Cryptosporidium in paper devices using enzyme retention assay showed potential for further improvement; however, this research provides initial proof-of-concept for paper-based microfluidic assays to detect infectious pathogens with high sensitivity using low cost materials and simple fabrication techniques.Biolog
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